Torpedo director



R. w. PITMAN TORPEDO DIRECTOR Jan. 1, 1952 8 Sheets-Sheet 1 Filed May 8, 1946 Jrwcwtoo RICHARD W. PITMAN %/w/% R. W. PITMAN TORPEDO DIRECTOR Jan. 1, 1952 s Sheets-Sheet 2 Filed May 8, 1946 gwuc/vvtm RICHARD W. PITMAN Jan. 1, 1952 w, PlTMAN 2,581,138

TORPEDO DIRECTOR I lul lllllll J6 7' I 88 v .3 i I A*l llu m VVWQWW 36 a I 89 RICHARD WPITM 23 2/ 2e 24 7 v I Jan. 1, 1952 w, p T A 2,581,138

TORPEDO DIRECTOR Filed May 8, 1946 s Sheets-Sheet 4 nus IHIHHIHHI-H I 3 SYWWHM' RICHARD w. PITMAN Jan. 1, 1952 w, HT A 2,581,138

TORPEDO DIRECTOR Filed May 8, 1946 8 Sheets-SheetS FIG.5

/6 2/2 83 3 rvuwwbo'o RICHARD w. PITMAN,

R. W. PITMAN TORPEDO DIRECTOR Jan. 1, 1952 8 Sheets-Sheet 6 Filed May 8, 1946 FIG. '6

l6 gwuv/wbo'o RICHARD'W. PITMAN Jan. 1, 1952 WPWMAN 2,581,138

TORPEDO DIRECTOR Filed May 8, 1946 V 8 Sheets-Sheet 7 2; 1 Z) O v x 0. I g 5 r I 7, 4/?) 6 y: QSJQ r 351? TIZI AN G 1.5

gwum'im RICHARD W. PITMAN R. w. PITMAN TORPEDO DIRECTOR Jan. 1, 1952 8 Sheets-Sheet 8 Filed May 8, 1946 Target Spegd RICHARD W. PITMAN oww Patented Jan. 1, 1952 UNITED STATES PATENT OFFICE TORPEDO DIRECTOR Richard W. Pitman, Philadelphia, Pa., assignor to the United States of America as represented by the Secretary of the Navy Application May 8, 1946, Serial No. 668,026

6 Claims. 1

The present invention relates to torpedo directors and, in particular, to such directors adapted for use in aircraft.

Up to the present time in torpedo directors, the solution of the vector triangle known as the torpedo triangle has been accomplished on an angle solver. Into the angle solver is introduced torpedo speed, target speed, and target angle, which is the bearing of the aircraft from the targets course at the instant of release. Several disadvantages are inherent in the methods now used. The pilot operating the torpedo director must estimate the target angle at which he wishes to drop the torpedo and set thi target angle on the director. He must also estimate the targets speed and place this into the director, the torpedo speed being known in advance. In order to secure a hit, it is necessary that the plane using these directors be at the proper target angle relative to the target ship at the instant of drop. If, because of anti-aircraft fire or other circumstances beyond the control of the pilot, the firing plane is unable to reach this predetermined target angle, or if the pilot makes a mistake in estimating the target angle, a miss will result.

The prior gyro-controlled instruments for determining the correct firing angle have been used with excellent results on surface and submersible water craft, and the accurate setting of these instruments i possible due to the low rate of speed at which the surface and submersible craft travel, thereby affording the operator considerable time to make numerous mathematical calculations, the results of which may then be set into the mechanism. Due to the high rates of speed of dive bombers and other torpedo launching aircraft,

the existing instruments are not adaptable to such craft. With the innovation of aircraft torpedo dive bombing, an urgent need for a gyro controlled firing sight confronted the designers, one that would require a minimum of adjustment and permit elimination of the usual time consuming mathematical calculations, and an instrument that would enable the pilot of such aircraft to first set his sights at the desired firing angle preliminary to making his bomb run while traveling at a high rate of speed and, secondly, to make corrections for change in direction or speed of target, should the target change its course or speed after the pilot has started his bomb run.

It is an object of the present invention to provide an improved torpedo firing sight adapted to be controlled by the usual airplane directional gyro while the airplane is traveling at a high rate of speed.

A further object of the present invention is the provision of an improved torpedo director into which the target'angle is continuously and autoadjustable to compensate for variations in average torpedo speed for any particular conditions taking into account its airborne travel as affected by a last minute change in aircraft speed or in altitude at which the torpedo is to be dropped.

A further object of the present invention is the provision of an improved director with means to enable alignment of the target vector in the director with the target course.

A further object of the present invention is the provision of means for adjusting the rear sight in accordancewith target speed, predetermined torpedo run, aircraft speed and altitude at time of firing.

Other objects and advantages will become apparent as the description proceeds and is taken in connection with the accompanying drawings wherein like characters of reference designate corresponding parts throughout the several views, and wherein:

Fig. 1 is a front perspective view in perspective of the improved torpedo director with cover removed and showing the director associated with a modified directional gyroscope, the solid line circular arrows indicating the path of the rear sight in its sighting movement in either direction, the dotted and dot-and-dash lines and arrows indicating the circle described when the rear sight arm is in two other positions of angular adjustment.

Fig. 2 is a side elevational View of the torpedo director and gyroscope, the cover and certain other parts being shown in section.

Fig. 3 is a top plan view of Fig. 1.

Fig. 4 is a front elevational view of the torpedo director and gyro mounting adaptor.

Fig. 5 is a view of the gyro adaptor and the torpedo director, partly in left side elevation and partly in central vertical longitudinal section.

Fig. 6 is a view of the gyro adaptor and the torpedo director, partly in rear elevation and partly in vertical transverse section.

Fig. 7 is a front elevational view of the director, portions being shown broken and fragmentary, an outer quadrant shaped dial portion beof the corrected target speed, torpedo water speed and the line of sight.

Fig. is a fragmentary perspective view of the director and gyro showing the automatic computing mechanism for positioning the rear sight ball in the proper relation with respect to I the front sight.

Fig. 11 is a perspective view of a closure cap for the adaptor.

The torpedo director shown in Fig. I is a mechanical instrument which gives the torpedo pilot a means for finding the course on which he should release. To do this it receives estimates of target course and speed, as well as information to correct for the airborne torpedo run, and provides continually a computed line of sight. If the aircraft is so maneuvered that this line of sight passes through the target, then the lead is correct and release may occur. During such maneuvers it is normally unnecessary to correct the setting of target course, since this setting is automatically stabilized and is unafiected 'by reasonable motion of the aircraft.

The instrument attaches to a modified directional gyro l0, when the latter is available in an appropriate position, and draws from that instrument the stability-in-azimuth required to storethe target course, once estimated. Connection to the gyro, in its installed position, is made by means of a bayonet joint and an adaptor !2 built on the gyro case. a A manual clutch 88 is provided, which, when disengaged, severs completely the operative connection between director and gyro gimbal.

The computed line of sight (the output of the director) is determined by the relative position of a ball-and-post combination atop the instrument.

In the operation of the torpedo director, the following instructions are meant merely to suggest a workable sequence of operations in the use of the director. They should not be interpreted in any degree as tactical doctrine.

When an attack is to be made, the torpedo plane will be initially at some distance from the target and presumably the gyro will be in use as a directional indicator. The plastic dust cover 55 on the director should first be removed by a straight vertical lift, without allowing it to bump the sight members. The next step in the attack is to throw the clutch lever 88 (see Fig. 1) all the way to the left. The gyro should next be caged by pushing knob l l in.

The speed and course of the target, if available, may next be incorporated. Target speed is set directly on the right-hand dial by means of knob I99. The target course is set by rotating the gyro caging knob H while pushed in, until the ship model is aligned parallel with the target, and with the same heading. The yrois then immediately uncaged by pulling knob H out; and the course or heading of the target will automatically be stabilized. If, while pre- .1 illustrated in Fig. 8 and showing the relations paring for the run, the target speed or course should difier from the values inserted, they may be reset without interfering with any other settings.

t is advisable to determine in advance at what altitude the torpedo will be released, and to set the altitude dial (H) to that value as soon as possible. It is much easier to alter the values of torpedo run or airplane speed after the attack has been started, than it is to change the altitude setting. Altitude is set, by a pull-turn operation of the left-hand knob 83, against the index arrow of the altitude scale. Similar- I ly, likely values of the torpedo run and airplane speed, for the moment of release, should be inserted, using the knob I83 to set the proper values on the corresponding scales I13 and 954 against one another.

The director with values set in and stabilized by the gyro is maintaining the course of the target. Ii.- the attack: can be made as blamed. the procedure is now simple. The target may be aligned with the sight ball and post-merely by flying the plane in the appropriate direction. In the face of serious enemy resistance, the torpedo plane may be maneuvered in any necessary manner while approaching in a general way the desired release point. The director will still indicate the solution of the preset collision problem, whenever the sights align uponv the target.

As the torpedo plane closes the range to reach the set value of the torpedo run, the set altitude and speed should be attained as quickly as possible. The course of the target may now be checked with the ship model and, if necessary, a last adjustment may be made.

When the proper release point has been reached, the target should be lined up with the sights. The axis of the plane and hence the torpedo will then be directed toward the collision point, and the torpedo. may be released.

The following is a condensed theoretical discussion of the conditions prerequisite for a torpedo hit. The distances covered, during, the total time from release to collision, by the torpedo and a uniformly moving target are simply their speeds multiplied by that time. Hence the distances themselves are proportional to the corresponding speeds. As seen in Fig. 8, where a triangular slice of ocean is shown, these same distances, together with the range along the line of sight at release, must form a triangle; and hence by the law of sines sin (lead angle) target run sin (target angle) torpedo run but these runs, or distances, have been shown to be proportional to the corresponding speeds; thus sin (leadangle) target speed sin (target angle) torpedo speed be made by dividing the first by a correction- Conversion from 5., Q, which involves principally the torpedo run and the aircraft speed and altitude at release. Instead of the last formula, then sin (lead angle) target speedXQ sin (target angle) torpedo water speed The easiest way to solve this equation and to obtain the proper lead angle is to set up a model triangle in a horizontal plane, which will simulate the real triangle of Fig. 8 and in which the .appropriate sides and angles will be in accord the target. The similarity of the model triangle to the real space triangle, in spite of the interchange of the positions of corresponding sides, is evident from a comparison between Figs. 8 and 9. In particular, it is seen that the lead angle 3 is completely determined by this method.

Thus, it may be seen that a model speed-triangle can be used to'solve the torpedo release problem. One side of the triangle is made proportional to the torpedo water speed and is fixed in the heading of the aircraft. Another side is made proportional to the estimated target speed, corrected by a multiplier Q, and is set parallel to the target heading and stabilized. The third, or remaining, side of the triangle provides a line of sight, which, if made to pass through the target by choosing the appropriate aircraft heading, automatically assures that that heading is satisfactory for release.

The correction Q compensates for the airborne run of the torpedo, and may be shown to be correctly accomplished through a fractional reduction in the length of the target speed vector. This fractional reduction must be directly proportional to the square root of altitude, inversely proportional to the torpedo run, and directly proportional to the difference between airplane speed and torpedo water speed.

To show how the complete solution is carried out mechanically within the director, it is necessary to show how the primary information set into the instrument is utilized to produce the ultimate line of sight.

In Fig. 10, the target speed dial A rotates the pinion B which moves the plate C by an amount corresponding to uncorrected target speed. At the left-hand side of the plate C, a stack of dials D, for setting in altitude, airplane speed, and torpedo run, computes the fractional reduction mentioned above, and delivers it as a rotation to the cam plate E, the radius of whose cam slot at any point controls the slope of the camfollower arm F pivoted on plate C. Bearing against the lower edge of this arm F is a pin G whose vertical position is a measure of the corrected target speed.

The position of pin G ultimately controls the vertical position of rotatable piston H and therefore also of a small overhanging platform I at the top of that piston. A small lever rigidly attached to'the bottom end of the ball boom M bears on the under side of this overhanging platform. I

The ball boom- M is independently pivoted on a horizontal axis attached to the stem J which sits in a socket in the gimbal of gyro L. By

means of the clutch K, this friction connection between gyro and director stem may be severed. As pin G rises or falls, due to the positioning imposed by rotation of the correction-cam E and of the, targetspeed pinion B, the ball boom M will be forced by the platform I to assume a position such that the horizontal displacement from the extended axis of the stem to the center of the sight ball represents the properly corrected target speed.

This target speed displacement; or vector, is positioned in space by caging and rotating the gyro with the clutch K engaged; the torpedo speed vector is represented in direction by the axis of the airplane and in amount by the distance between the sight post N and the zero position of the ballboom M (which is the extended axisofthestemJ). V

The target speed vector and the torpedo speed vector have now been combined properly as shown by the triangle at O, and when the target is lined with the sights the axes of the airplane.

and torpedo are directed toward the collision point. y

This torpedo director is used with a directional gyro which has been modified in such a way that a connection to the vertical gimbal may be effected through the top of the gyro case as shown in Fig. 10. When made available as a standard directional instrument this gyro simply has a cover over the opening in the top of its case. An adaptor housing l2 forming the external part of a bayonet joint and carrying a pneumatic connection 288, replaces this cover when the gyro is to be used with the torpedo director. A new gasket, supplied as part of the equipment, should be used whenever such a re-' placement is made.

To the gyro with adaptor housing may be fitted either the director equipment, as best seen in Fig. 2, or the replacement cap 211, Fig. 11. A sponge-rubber washer 215, shown in Figs. 2, 4, 5 and 6, is placed around the neck of the adaptor housing in either case. The replacement cap 2| 1 may be substituted for the director when the latter is not in use.

Whenever the director is connected to or disconnected from the gyro, that is to say whenever the bayonet joint is engaged or disengaged, it is recommended that the plastic dust cover 55 be placed on the director component for facility in handling. With regard to the dust cover a word or two of caution is in order. Whenever the cover is placed on the director, the clutch lever 88 (see Fig. 1) should be thrown all the way, to the right: to the gyro free position. In attaching or removing the cover, care should be exercised so as not to strike the members of the sighting system.

Before attaching (detaching) the director component to (from) the gyro, by means of the bayonet joint, the target speed dial I98 (Fig. 1) should be set at 40 knots and the clutch lever shifted to its extreme right position. The director is attached to the gyro by inserting the bayonet joint into the adaptor housing in such a way that the bayonet pins enter the corresponding slots in the housing.

Dust and dirt are the principal enemies of the director; the plastic dust cover should always be clipped to the director when the latter is not in use. When the director is removed from the gyro, the gyro should becovered to prevent entry accuse washer 2 l) zshould'be kept in theadaptor on the gyro.

As to the effect .ofthe director on the performance of the gyro, it should first be remarked that there is no physical connection between the two when the clutch lever 88 (Fig. l) is thrown to the right. Even with the director clutched .in, clutch lever to the left, it should be next to impossible to observe any loading of the gyro. With the director thus stabilized, it should be possible to make at least two complete 2-minute turns without causing excess drift of the gyro card. If a director loads the gyro appreciably it is mechanically in disrepair and should not be used.

Going .back to the construction of the mechanism for reproducing the model triangle in the director, and referring to Fig. 9, the shape andcooperation of the adjusting parts is based on the following considerations. As already briefly explained, the equation of the actual speed triangle may be written (1) sin 5= sm o:

axes of the front and rear sights is fixed in accordance with the torpedo water speed, and to make corrections for the airborne travel of the torpedo to arrive at the proper line of sight, a correction factor may be applied to the target speed vector instead of the torpedo speed vector according to the following calculations:

The torpedo run where K is a constant to reconcile the units, T is the total time for torpedo run, Tf the time for airborne torpedo run (time of flight through the air), Vt is the torpedo water speed and Va is the airplane air speed.

From (2) Transposing the first terms on each side of the equation and dividing through by (K-R.)

V,T KR T (Vu-V,) KR KR KR Substituting (VtaT) for KR in the left side of the equation and simplifying:

.L Vn KR(VG i) .Or,;since the timeof flight of the torpedo Tris merelythe fall-timefrom altitude H,

then, from (3) which is the correction :factor Q "where K is a dimension-constant different from X. If K is evaluated .for thevalue of g-infeet/secfi, and for the :unitsof the variablesinknots for thespeeds andfeet for altitude, we have L E v.5 7.1212 Multiplying the right hand side of Equationlby is inserted for targetspeed (1) then the average torpedo speed Va may be replaced by torpedo waterspeed Vt- In the airborne correction dials of the mechanism, only H, .R, Va are set in. Vt as already mentioned is a constant of the apparatus and is set for 40 knots in the device shown.

Referring again to the drawings, the numeral H designates a knob connected in a standard manner to cage and .uncage the gyro by a pushpull motion, and to adjust the gyro in azimuth when caged, by a turning motion. The adaptor I2 is secured to the gyroscope H) by screws 14 shown in dotted lines in Fig. 2 of the drawings. interposed between the top of the gyroscope casing l5 and the adaptor I2 is a gasket 16.

The torpedo director I3 comprises a cylindrical housing member I! in which are mounted certain opesating mechanisms to be enumerated and described in detail hereinafter. The housing member H has a reduced portion 3 and an integral flange [9. In the wall of the cylinder l'i there is provided an opening .in the form of a cam slot H, the lower wall 22 of the cam slot 2! being disposed at an angle and of irregular configuration and having recesses 23 and 24 for a purpose to be later described. Extending downwardly from the top of the cylinder IT, in the wall of the reduced portion 18 is a slot 25 that receives anadjustable stop 26 having a threaded shank 21 that is engaged by a nut 28 that secures the stop in an adjusted fixed position, and diametrically opposite the slot 25 is a slot 29. The lower portion 30 of the cylinder I1 is provided withstuds 3.! that may be integral'with the wall of the cylinder or, as shown in Fig. 5, they may be threaded into the wall of the cylinder.

Mounted upon the flange i9 is aplate 32 of sub stantially triangular configuration that is provided with a central opening 33 of a diameter to snugly engage the peripheral wall 34 of the housing H. The plate 32 is fixedly secured to the flange l9 by screws or rivets 35. Upon the plate 32 and secured thereto by any suitable means is a bar member 36 having a trackway groove 31 and anoblong opening 38. Adjacent the apex-39 of the plate 32, .there'are provided apertures 4| and 40 that receive interchangeablya lug 42 and a screw threaded shank 43 that depend from a block 44 as indicated by dotted lines in Figs. 2 and 5. The block 44 is rigidly secured to the plate 32 by a nut 45 that engages the threaded shank 43. superposed upon the block 44 and secured thereto by any suitable means is a tapered front .sight post 43, .a portion of the base of the post being approximately .uniplanar with the wall 41 of the block 44. The tapered portion of the front sight extends to a pointrepresented by the numeral 48 and .at this point the post is :of :a reduced size and of a uniform diameter at 49, and may be of any suitable length, the portion v50 being provided with a white sight line I and a companion line diametrically opposite. the line 5I. On the plate 32 adjacent one side wall of the block 44 there are provided numerical indicia 52 for a purpose to be later described. The plate is also provided with studs 53 and an indicia plate 54, the studs engaging clips(not shown) that are secured to the inner walls of a protective translucent cover 55 shown in Fig. 2 of the drawings.

Mounted. for slidable movement within the housing II is a sleeve 56 having a restricted portion .57, a bore 58 and-enlarged end portions 59 and66. The restricted portion 57 is provided with an openingBI for a purpose to be later described. The end portion 59 is provided with a bore 62' of greater diameter than the bore 58, to form a seat 63. In the wall of the end portion 59 is a threaded aperture 64 that receives the threaded end 65 of a pin 66. Diametrically opposite the threaded aperture 64 is a slot 67 that houses the head of the adjustable stop 26. The end portion 59 has a reduced portion 68 and within the walls of the reduced portion 68 there are provided vent bores 76. The outer diameter of the portion 68 being of smaller diameter than the remainder of portion 59, a space II is formed between the inner wall of the reduced portion I8 and the outer wall of the reduced portion 68. A race of bearing I4 is received fixedly in the bore 62.

Mounted for slidable reciprocating movement in the bore 58 of the sleeve 56 is a cylindrical member I5 having a head I6, a bore ll in the head, a hollow portion 78, a wall I9 having a bore 86, and a diametrical slot 86 for passing the pin 86", the lower end of the cylinder being provided with a flange 8|. The mouth of a bore 13 receives a closure cap 82 having a flange 83 and a recess 84, the flange 83 engaging the flange BI of the cylindrical member 15. In the head I6 there is provided a threaded bore 85 that receives the threaded shank 86 of a lever arm 81, the opposite end of the arm being provided with aknob 88 that is. secured to the arm by a screw 89. Within the end portion 86 is a spring 96 that encompasses the cylindrical member "I5, one end ,of the springengaging the seat I2, the opposite end of the spring engaging the inner face of the flange 8|.

Within the sleeve I5 there is mounted a tubular member 9| having an upper portion 92 and a lower portion 93. The upper portion 92 is provided with a slot 94 and a triangular shaped flange 95, a half portion of the tubular member diametrically opposite the slot 94 being cut away. The tubular member has an annulus 96, the lower face of which rests on the top face of the bearing I4. The upper portion 92 of the tubular member 9| is encompassed by the race of bearing I4, the lower reduced portion 93 passing through the bore 11 and terminating adjacent the lower wall of the head I6 and it is to be noted that the bore 11 is of greater diameter than the reduced portion 93. In the upper bore 69 there is positioned a retaining dust cap 99 having a bore I66 that engages the portion 92 of the member 9|. The cap 99 is provided with a recessed bore I6I that receives the annulus 96.

Within the tubular member 9| there is mounted for slidable movement a rod I62 that is provided with annuli I63, I64 and I65 (Fig. 6), the rod extending downwardly through the tubular memher, the end I 66 of the rod I62 terminating ad jacent the Wall I9. The lower portion I66 of the rod I62 is split as indicated by the numeral I01 and it is provided with an internal threaded portion I68 that receives the threaded portion I69 of a rod. II6, that has an annulus I I I adapted for engagement with the wall I9, the rod II6 adapted for slidable movement through the aperture H2 in the guide closure dust cap 82. The lower portion H3v of the rod 6 is of a reduced diameter, the end II4 having a tapered point. To the annulus I65 is mounted a U-shaped member I I5 that is secured to the annulus by a screw I I6 as shown in Fig. 6, the U-shaped member having legs III and arms II9, the legs being provided with an aperture I 26. Interposed between the legs I IT is a pivoted sight member I2I that comprises a base portion I 22 in the form of an arm, the end of the arm terminating in a tongue I23 that is in engagement with the flange of the tubular member 9I. Extending vertically from base portion I 22 is a rod portion I23 that is provided with an aperture that receives a pivot pin I24, the pivot pin having reduced pintles I25 that engage .the apertures I26 in the legs II I of the U-shaped member H5. The movable sight I2I has an enlarged portion I26, a reduced upper portion that merges into a tapered portion I27,'the end of the tapered portion being provided with a sphere I 28. Convoluted around the pivot pin I24 is a spring I29 having one leg I 36 secured to the rod portion I23, the leg I3I being secured to one leg of the U-shaped member at I32. A cover cap I33, having an internal diameter greater than the reduced portion I8 of cylindrical housing I I, is positioned over the tubular portion I8 of the member I! and it is secured in place by a bolt I34 that passes through an aperture in the top of the cap I33 and is received in a threaded aperture in one of the arms II9 of the U-shaped member II5. On the top face of the cover cap I33 is a block member I35 that is provided with a groove I36 in which groove is mounted a ship model I31. Thecover cap I33 is provided with a diametrical slot I38 that is of a width greater than the diameter of the lower portion I26 of the sight I2 I.

On the plate 32 and secured thereto by any suitable means is an L-shaped bracket I 39 that is provided with a track-way groove I46 that is in spaced alignment with the groove 31. Mounted for slidable movement in the grooves 31 and I46 is a plate member I4I having a bearing I42 thatmay be integral with the plate member, the top of the plate member having a cut out portion I43 that engages the groove I46, the cut out portion terminating adjacent the ends of the plate, the projecting ends forming stops I44 and I45 for limiting the movement of the plate member I4I. Secured to the plate member MI and held in spaced relation therefrom by a block I46, as shown in Fig. 3 is a plate member I 41 having side walls I48 and I49 that are approximately of semi-circular configuration and in which are mounted brake shoes I5I and I52. The front face of the plate I 41 is provided with graduations I53 that are adjacent the side wall I48, and adjacent the graduations I53 are indicia I54 that read in knots from I66 to 256, and a letter V. The face is further provided withan arrow I55 that is adjacent the side wall I49.

Secured to the bar member 36 by screws I 56 is a rack-bar plate I51. The slidable plate member.

I is provided with an aperture I58 in which is agsanrss I1 rigidly mounted one end I59 of atubular; shaft member I60. The shaft ISIlhas a reduced: portion IBI, a bore I62, an aperture: I 63 and abore I64. Rotatably secured to the shaft portion IoI is a disc I65, the disc having a helical. slot I55, and a pin I61 that is anchored in the disc I65 by any suitable means. Mounted on the shaft I09 and. in spaced relation from the disc I65 is a dial I68 having an. arcuate slot I99 through which the pin I01. passes. The dial I60 is, furthen provided with a stud I10 and a circumferential groove III that is engaged by the brake shoes I51. The face of the dial IE8 is provided with graduations I12; the letter R standing for range and an arrow for the altitude scale, and adjacent the graduations are indicia I19 that read inhundredsof. yards from, 8 to 2i, i. e., for values of R- from 800 to 2400 yards. Within the bore I54 is a. spring I14. that is held in the bore by a bolt screw I15, the head I10 of the bolt screw being housed in the bore I62 and it is to be noted the outer face of the head I16 of the bolt screw is normally coplanar with the end wall I11 of the shaft member I60. The end portions I18 of the bolt screw I passes through the aperture I19, the threaded portion I80 engaging a threaded aperture I8I in a disc I82 that is secured to a slidable cap I83 in any suitable manner. The cap I33 has a knurled knob I84, a semi-circular dial portion I85 and a quadrant portion I85 that is provided with the letter If standing for height, or altitude. The edge I81 of the dial I85 is. provided with graduations Hi8 and with numerical indicia I89 that are read in hundreds of feet, the graduations being spaced for altitudes from 80 to 400. The rear face of the quadrant I86 is provided with sockets I90 that are adapted for engagement with the stud I10. To the rear 7 face of the plate member I4I there is mounted an arm IBI that is held to the plate for pivotal movement by a pivot. I92, the lower face of the arm engaging the pin 66. The arm ISI is pro vided with a finger I93, and secured to and disposed at right angles to the finger is a pin I94 that engages the helical groove I58 for a purpose to be later described. In the bearing I42 is mounted a shaft I95 that carries a gear I96 that engages teeth I91 of the rack bar plate I51. A dial I98 having a knob I99 is fixedly mounted on the shaft 195, the circumferential edge of the disc having a groove 200 that receives the brake shoes I52. The front face of the. dial is provided with graduations 20I and indicia 202 that comprise the S scale calibrated in knots of target speed from 0 to 45.

The adaptor I2 comprises a cylindrical body 263 having an annular collar 204 and an axial bore 205. In the body 203. is a threaded bore 200 that is in communication with the bore 205, that receives the male threaded shank 201 of a pipe 208, the opposite end 209 of the pipe having internal threads (not shown) for connection to an air suction line to provide a flow of air into the gyro case for operating the gyro in a well known manner. The collar 204 is provided with slots 2I0 having an L-shaped portion 2H for the purpose of cooperating with the studs 3| on cylinder I1 to form a bayonet joint. In the bore 205 is positioned a spring 2I2, the lower portion of the spring seating in a recess 2I3, the upper portion of the spring engaging the end wall 2I4 of the cylinder I1. Encircling the collar 204 is a sponge rubber gasket 2I5, the lower face of the gasket seating on the face 2I6 of the body 203. The replacement cap 2I1 shown in Fig. ll in- 1 2 cludes a cylindrical. plug: portion. I1. insertible into the adaptor collar 2.04 and radially projecting pins 3| cooperating. with the bayonet: slots 2m in the. usual. manner.

In theoperatiorr of. the device the. torpedo director is mounted to the gyroscopein thefollowing manner, the. lower. portion 30. of the cylinder I1. is inserted into the collar 204 of. the mounting post I2, and during the. insertion,. the rod. portion II 0 is received inafriction grip bearing Pin. the gyro gimbal Q, the studs 3| being positioned in. vertical alignment with the slots 2I0. in the. collar; 2.04.. When. the studs are; in alignment with theslots. 2I.0. a downwardpushis exerted onthe dust, cover 55,.this' downward push compresses. the. spring 2I2. and the. director at this point. is turned clockwise untilv the front of the .plate32 is parallel with the. front of the gyroscope, the studs. 3I engaging the notches in the, ends of the L-shaped portions. 2 of the slots 2I0. The director assembly is held in this position by the spring 2I2.

The lever knob 88 permits the use of the gyroscope as a directional indicator when the lever is pushed to the right, which is the gyroscope free position, as indicated on. the plate 54,, and. this action lifts the end of pin IIO from contact. with the. grip bearing P in the gyro gimbal. During the movement of the lever arm 81 the, following action takes place: the arm 81' rides the inclined wall 22 of the cam slot 2I until it drops into the notched portion 24 as shown in Fig. 1 of the drawings, the member 15 rotates upwardly; and in a spiral direction, bringing, the wall 19 in.contact with the annulus II I thereby lifting ,the rod I 02, U-shaped. member II5,,cap member I33 and rearsig-ht member. I2.I. The movement of. the above parts disengages the end H4 of rodportionv I13 from the friction bearing. in the, gyro gimbal.

When the lever; knob 0.8 is pushed. to the: left, which is the. gyro stabilized position as indicated on the plate 54, the directoris connected. to. the gyroscope through the. movement. and contact. of the following parts. The. arm 81. rides. the in.- clined .wall 22;.0f.the;CaIn S10t2 and drops into the notched portion. 23' during movement of the lever. arm, the. member 15 towhich .the arm- 81 is. connected, spirally turns. and moves downwardly through the action of. the spring the rods I02 and H0 being forced downwardly through the action of: the spring I29that-forces theIend: II L-of rod portion 3- into gripping relation with the friction bearing in the gyro gimbal.

Asshown. in-the drawings, the-setting dialsare three innumber; the two on the left I 68- and 1-05 are in stacked relation with the disc I 65 on the shaft I60, and these dials byadjustment relatively to each. other and tolthe scale I54 on plate I41, are for setting the flight-constantsto allow for the airborne travel of the torpedo, while the dial-on the right I98 is: for-'thetarget-speed setting -dial..

The three airborne correction scales from inside out L89, I13 and I54: are for setting H, R and Vg'where:

I-I=altitude, in feet, of the torpedo at-moment of release..

R=run, or future range, or slant range, or torpedo traverse;v i. e.,. the actualhorizontal air plus water travel of the,- torpedo. between release and collision with the target.

. V =the ground speed of the torpedo plane along the run, at the moment of release of the torpedo. v

The H-scale is graduated in feet from 80 to 400 and is set to the index by pulling out the knurled knob I84 until the stud I10 is free from the apertures I96, and turning the knob until the proper altitude indicated on the scale I89 falls on the index or arrow point on the dial I68. When the knob is released, the scale will settle into position, and be locked to the dial I68 by one of the apertures I90 engaging the stud IIII.

For the R-scale or Vg scale there is no index, these circles being set by setting the proper values opposite each other. As previously described, the R-scale is graduated in hundreds of yards, from 8 to 24, i. e., for values of R from 800 to 2400 yards. The V scale is graduated in knots from 100 to 250.

For a torpedo launched at a distance of 1800 yards from the collision point, from a plane traveling at a ground speed of 200 knots, the 18 on the R-scale is set opposite the 200 or" the Vg scale. In all directors, the V or target-speed dial is calibrated in knots from 0 to 45.

When an attack is to be made, the torpedo plane will presumably be at some distance from the prospective target and the gyroscope II] will be in use as a directional indicator. The first step in the attack is to engage the director I2 with the gyroscope III by throwing the lever knob 88 to the left as far as it will go,-this being the director stabilized position. The speed and course of the target must next be estimated, the target-speed in knots is set on the 'Vs dial I98, the target course is set by rotating the gyroscope knob II in pushed in or gyro-caged position until the ship model I3 'I on the dust cap I33 of the rear sight post I21 is aligned parallel with the tar-get with the same heading. When the gyroscope I0 is uncaged by pulling knob II out, the course and heading of the target as represented by the ship model will be stabilized by the gyro. If, during the course of the next few moments, while preparing for the run, the target speed or course should seem to have been incorrectly estimated, the director may be reset by use of the knob II without interfering with any other settings being made. The altitude at which the torpedo is to be released is preferably planned in advance and the H-dial I85 set accordingly. It is mucheasier to alter the values of run or ground speed, after the run has been started, than to change the H-setting.

Likely values of the future range and ground speed, both for the moment of release, are next set by setting the proper values on the R and V scales opposite each other.

The director with values set in and stabilized by the gyroscope I0 is maintaining the direction and speed of the target. If the attack can'be made as planned, the procedure is as follows: The actual target is aligned with the sights 49 and I2! by flying the plane in the proper. direction. If enemy resistance becomes annoyling, the torpedo plane may be flown any way deemed desirable, while approaching in a general way the desired release point; the director will continue to indicate the solution of the collision problem.

As the torpedo plane approaches the proper value of the future range, the pre-set altitude and ground speed should be attained as quickly as possible. The course of the target should be check with the .ship model I31, on the director,

and, if necessary, a last adjustment. of this variable should be. made with the knob IIby caging the gyro. 1

When the proper release-point has been reached the target must be lined up with the sights 49 and NH, whereby the axis of the plane (and hence of the torpedo) will be directed toward the collison point; and the torpedo may then be released.

With the director in stabilized position, the rod I I0 is in frictional contact axially with the gyro gimbal and movement of the knob I I in its gyro caged position in a clockwise or counterclockwise direction imparts turning movement to the following members, rod III'I, rod I92, U-shaped member II5, cap I33 and rear sight I2I, where+ by the ship model I3I may be brought in parallel alignment with the target with the same heading, for the purpose described above. 7

Target speed in knots is set on the Vs dial I98 as follows: Assuming that the 0 on the dial I98 is in line with the arrow V and that the dial I 98 is to be set for a 40 knot target speed, the dial is rotated in a clockwise direction until the numeral 40 is in line with the arrow V. As a result of movement of the dial, the gear I96 on the shaft I95 is rotated and engages the teeth in the rack bar plate I51, imparting movement to the slidable plate member I4I, the plate with all the dials mounted on it moving to the right. The arm I 9I that is privotally mounted on the plate MI and disposed at an inclined angle, is in engagement with the pin 66 that is secured to the sleeve member 51, the sleeve member 57 being urged upwardly against the lower edge of arm I9I through the action of the spring 56. As pin 66 is moved, sleeve 51 moves member 93, member 95 causing sight member I2I to move on its pivot I24 under the tension of the spring I29. Adjustment of the target speed set ting thus adjusts the leverage of arm I9I acting on pin 66 to afiect the amount of displacement of the rear sight I28.

The altitude at which the torpedo is to be released, when determined, is set on the I-I-dial. To do this the knob I83 is pulled outwardly and rotated either in a clockwise or counterclockfise direction until the determined number of feet in hundreds on the I-I-scale is in line with the arrow or index on disc I68. By way of example, if the torpedo is to be released at 200 feet, the knob is turned until the number 2 mark on the scale is in line with the arrow on dial I68, and then released, whereupon the proper socket I96 will accommodate the pin I19 to lock the dial in proper relative position.

In this setting the following operation takes place, as the knob I83 is pulled out, which is integral with the H-dial I85, one of the sockets I96 therein is disconnected from the pin I'IIl on the dial I68. The-H-dial is connected to the disc I65 by the pin I61 and as the H-dial I85 is rotated in either direction the disc I65 is also rotated, thereby imparting movement to the arm I9I through the pin I94 that engages the helical groove I66, in the disc I65. This movement of the arm I9I effects either an upward or.

downward movement of the pin 66 carried by the cylinder 56 depending upon the direction of rotation of the I-I-dial I85. As the cylinder 56 moves up or down, rear sight I2I is moved either away from or toward a vertical position, the following members causing this movement; the tubular member 9| and its flange 95 carried by the.

cylindrical member 56, the portion I22 of the.

memes 15- rear sight PM which is held in contact with. the flange 95 by the spring I29, thereby causing the rear sight l2! to move on its pivot 2.242s the pin 66 is raised or lowered.

For setting the knob i83 ior'the range between the release and collision with the target and the groundspeed of the aircraft, the dials I85, 168 and disc H35 are in locked engagement, the dial I85 being locked to dial Hi8 through pin llil. Disc I85 is in locked engagement with dial 185 by the pin I81 carried. by disc 1.55 passing through the arcuate slot its in dial I63, and projecting into a registering aperture in dial l85.

Assuming the range to be 1806 yards and the ground speed of the aircraft to be 200 knots, the knob I83 is rotated until. 18 on dial E58 is opposite 290 on the Vg or ground speed scale on plate 14?. The movement, during this adjustment, of the dials 55, ltd and disc 155 as a unit affects the arm I95, pin 66 and rear sight I21 in the same manner as previously described during the torpedo altitude setting but by an amount corresponding to the correction (Q) of'the target speed vector to compensate for the airborne travel of the torpedo under the herein assumed conditions.

As shown in Figs. 1 to 7, the front sight post in the position marked 1 at 52 on the base plate 39, is mounted at a distance from the rear sight axis representing the torpedo run vector of a torpedo having a water speed of l knots. Provision is made, however, for reversing the mounting of this front sight with respect to the two openings 45 and Al in the base plate 39 by removing the post from the position shown and reinserting it so that the stud it goes through the opening ll and the pin 22 is in the opening 49. With the post mounted in this position which is indicated by the numeral 2 inscribed at 52 on the base plate so, the distance between the front sight post and the axis of the rear sight is proportionately decreased to represent the shorter torpedo run vector corresponding to a torpedo having a water speed of 33.5 knots. These are the speeds of the two standard torpedos in general use. However, the front sight post may be made adjustable as to its distance from the rear sight axis so as to conform to any speed of torpedo, as indicated by the slidable mounting connection shown in Fig. 10.

The helical cam groove its on plate i823 is formed so as to move the lever it and therefore the pin 66 and shoulder 95 and thereby also the rear sight ball H23 in accordance with the correction Q necessary to be applied to the target run which is represented by the horizontal distance between the sight ball and the vertical axis of the rear sight. As previously explained, the correction factor Q is directly proportional to the square root of the altitude, inversely proportional to the future range or torpedo run, and directly proportional to the difierence between airplane speed and torpedo water speed. These proportions are properly scaled in the instrument with respect to the shape of. the helical cam slot I66, the scale of values of the several scales used, and the representative distance between the axes of the front and rear sights, so that accurate results may be obtained in any positions of the adjustments.

The presentdisclosure is a duplicate of that de scribed in copending application Serial No. 658,724; of Robert M. Freeman for Torpedo Directors, filed April. 1, I946, which includes the invention of the claims. This. invention. comprises the. novel com. pact mechanism for computing airborne correction directly in the instrument and its linkage to the dirigiblerear sightpost.

It will be understood that the above description. and accompanying drawings comprehend only the general and preferred embodiment of the invention. and that various changes in construction, proportion and arrangementv of the parts may be. made within the scope of the. appended claims without sacrificing any of the advantages of the invention.

What is claimed is:

1. For use with a directional gyro provided with a member. stabilized in azimuth, a torpedo director including a normally vertical shaft mounted for angular orientation about. its axis and connected to said member for stabilization in any one of a plurality of angularly oriented positions representative of different target. directions, a sight arm pivotally connected to said shaft for swinging movement into any one of a plurality of positions of angular adjustment relative to said shaft, a sleeve relatively reciprocable coaxially of said shaft and adapted through said relative movement to control the angular position of said sight arm relative to said shaft, manually adjustable means for setting the reciprocable sleeve and thereby disposing said sight. arm in an angular position relative to said shaft representative of target speed, and a normally vertical sight spaced from said pivoted sight arm a. distance. representative of torpedo speed.

:4. For use with av directional gyro including a housing and provided with a member stabilized in azimuth, a torpedo director including a bracket adapted to be attached to the gyro housing, a normally vertical shaft mounted in said bracket for angular orientation about its axis and connected to said gyro member for stabilization in any one of a plurality of angularly oriented positions representative of difierent target directions, a sight arm pivotally connected to said shaft for swinging movement into any one of a plurality of positions of angular adjustment relative to said shaft, a sleeve reciprocable in said bracket coaxially of said shaft and adapted to control the angular position of said sight arm relative to said shaft, manually adjustable means carried by said bracket for setting, the reciprocable sleeve and thereby disposing said sight arm in an angular position relative to said shaft representative of target speed, and a normally vertical sight releasably fixed to said bracket and spaced from said pivoted sight arm a distance representative of torpedo speed.

3. For use with a directional. gyro including a housing and provided with a member stabilized in azimuth, a torpedo director including a bracket adapted to be attached to the gyro housing including a normally vertical hollow cylindrical portion, a sleeve reciprocable in said cylindrical portion, a shaft coaxially mounted in said sleeve for angular orientation about its axis and connectible to said gyro member for stabilization in any one of a plurality of angularly oriented positions representative of different target directions, a sight arm pivotally connected to said shaft for swinging movement and disposed through engagement by said reciprocable sleeve in any one of a plurality of positions of angular adjustment relative to said shaft, manually adjustable means carried by said bracket for setting the reciprocable sleeve and thereby disposing said sight arm present applicant as defined in the appended in. an angular position relative to said shaft 17 representative of target speed, and a normally vertically sight releasably fixed to said bracket and spaced from said pivoted sight arm a distance representative of torpedo speed.

4. For use with a directional gyro including a housing and provided with a member stabilized in azimuth, a torpedo director including a bracket adapted to be attached to the gyro housing including a normally vertical hollow cylindrical portion, a sleeve reciprocable in said cylindrical portion, a shaft mounted in said sleeve for angular orientation about its axis and connectible to said gyro member for stabilization in any one of a plurality of angularly oriented positions representative of difierent target directions, a sight arm pivotally connected to said shaft for swinging movement and disposed through engagement by said reciprocable sleeve in any one of a plurality of positions of angular adjustment relative to said shaft, said sleeve being provided with a projection, a bar supported for horizontal reciprocatory movement on said bracket, a lever pivoted to said bar for reciprocatory movement therewith and for vertical swinging movement, said lever engaging said projection for controlling the vertical position of said sleeve, manually operable means setting the bar in any one of a plurality of horizontally spaced positions representative of target speed, manually operable means setting the lever in any one of a plurality of angularly spaced positions representative of airplane speed, altitude and torpedo run, and a normally vertical sight spaced from said pivoted sight arm a distance representative of torpedo speed.

18 lever, an airborne correction dial rotatably mounted on said axle for angular adjustment, and means releasably connecting said correction dial to said cam in any selected one of a plurality of angularly spaced relationships.

6. The torpedo director specified in claim 4, said lever setting means comprising an axle carried by said bar, a rotary cam mounted for angular displacement on said axle and adapted to angularly position said vertically swingable lever, first and second airborne correction dials rotatably mounted on said axle, for angular adjustment and provided with range and altitude correction indicia respectively, means transmitting rotary movement of said second correction dial to said cam, and means releasably connecting said second correction dial to said first correction dial in any selected one of a plurality of angularly spaced relationships.

RICHARD W. PI'IMAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date D. 144,108 Freeman Mar. 12, 1946 1,997,303 Le Prieur et al Apr. 9, 1935 2,317,059 Hilton et a1 Apr. 20, 1943 2,384,036 Klemperer et al. Sept. 4, 1945 2,421,749 Freeman June 10, 1947 2,534,258 Gallery Dec. 9, 1950 2,547,654 Moore Apr. 3, 1951 2,557,103 Hammond June 19, 1951 FOREIGN PATENTS Number Country Date 870,388 France Dec. 12, 1941 

